Macsyma package for celestial mechanics

I would like to make my hobby time somewhat easier.
I would be interrested in a Macsyma package for celestial mechanics.
I am first interrested by secular pertubation theory and using the Lagrange/Poisson bracket algebra.
I have too little time and patience to develop such calculation by paper and pencil ... but I would enjoy a computer-algebra solution.

As a first test of such a package, I would try to simply re-derive the well-known Lagrange perturbation equations for the elements of an orbit. A package restricted to this special case would already be useful.